阅读说明：本技术 一种提高弯轨处列车定位精确度和有效性的方法及系统 (Method and system for improving positioning accuracy and effectiveness of train at bent rail ) 是由 郭军强 张�浩 李莹莹 焦名 于 2019-09-26 设计创作，主要内容包括：本发明公开了一种提高弯轨处列车定位精确度和有效性的方法,所述方法包括以下步骤：获取电子地图中弯轨处相邻两个卫星参考点之间的弧线长度和线段长度；根据所述弧线长度与线段长度的差值决定是否添加新的卫星参考点；根据卫星定位点和所述卫星参考点进行垂线匹配算法；基于所述垂线匹配算法的结果决定所述卫星定位点映射的位置。本发明通过对现有电子地图和垂线匹配算法进行扩展,针对电子地图增加一定数量的卫星参考点,并对垂线匹配算法进行优化,以提高列车卫星定位的精确度和有效性。(The invention discloses a method for improving the positioning accuracy and effectiveness of a train at a bent rail, which comprises the following steps: acquiring the arc length and the line length between two adjacent satellite reference points at the curved orbit in the electronic map; determining whether a new satellite reference point is added or not according to the difference value between the arc length and the line length; performing a vertical line matching algorithm according to the satellite positioning point and the satellite reference point; and determining the position mapped by the satellite positioning point based on the result of the vertical line matching algorithm. The invention expands the existing electronic map and the vertical line matching algorithm, increases a certain number of satellite reference points for the electronic map, and optimizes the vertical line matching algorithm so as to improve the accuracy and the effectiveness of the train satellite positioning.)

1. A method for improving the positioning accuracy and effectiveness of a train at a bent rail is characterized by comprising the following steps:

acquiring the arc length and the line length between two adjacent satellite reference points at the curved orbit in the electronic map;

determining whether a new satellite reference point is added or not according to the difference value between the arc length and the line length;

performing a vertical line matching algorithm according to the satellite positioning point and the satellite reference point;

and determining the position mapped by the satellite positioning point based on the result of the vertical line matching algorithm.

2. The method for improving the accuracy and effectiveness of train positioning at curved tracks according to claim 1,

the specific step of determining whether to add a new satellite reference point according to the difference between the arc length and the line length is as follows:

judging whether the difference value between the arc length and the line length is greater than a first threshold value, and executing a processing step according to a judgment result, wherein the processing step comprises the following steps:

if the difference value between the arc length and the line segment length is larger than a first threshold value, adding a new satellite reference point between the two adjacent satellite reference points, and returning to the step of obtaining the arc length and the line segment length between the two adjacent satellite reference points at the bent orbit in the electronic map;

and if the difference value between the length of the arc line and the length of the line segment is not larger than a first threshold value, executing the next step.

3. The method for improving the accuracy and effectiveness of train positioning at curved tracks according to claim 1,

the algorithm for matching the vertical line according to the satellite positioning point and the satellite reference point comprises the following steps:

making a vertical line of a connecting line of the two adjacent satellite reference points through the satellite positioning point;

judging whether the drop foot is on the connecting line of the two adjacent satellite reference points, wherein the judgment result comprises the following steps:

if the plumb feet are on the connection line of the two adjacent satellite reference points, the vertical line matching is successful;

and if the plumb is not on the connection line of the two adjacent satellite reference points, the plumb line matching fails.

4. The method for improving the accuracy and effectiveness of train positioning at curved tracks according to claim 1,

the determining the position of the satellite positioning point map based on the result of the vertical matching algorithm comprises:

if the vertical line is successfully matched, mapping the satellite positioning point to a vertical foot;

and if the vertical line matching fails, judging the position of the satellite positioning point.

5. The method for improving the accuracy and effectiveness of train positioning at curved tracks according to claim 4,

the positions of the satellite positioning points comprise:

the satellite positioning point is near the nearest satellite reference point;

the satellite fix point is not near the nearest satellite reference point.

6. The method for improving the accuracy and effectiveness of train positioning at curved tracks according to claim 5,

if the satellite positioning point is close to the nearest satellite reference point, mapping the satellite positioning point to the nearest satellite reference point, and successfully positioning;

and if the satellite positioning point is not near the nearest satellite reference point, the positioning fails.

7. The method for improving the positioning accuracy and effectiveness of trains at curved rails according to claim 5 or 6,

judging the position of the satellite positioning point by the following steps:

making an extension line of a connecting line of the two adjacent satellite reference points;

making a perpendicular line of the extension line through the satellite positioning point;

and determining the position of the satellite positioning point according to the distance between the foot and the nearest satellite reference point.

8. The method for improving the accuracy and effectiveness of train positioning at curved tracks according to claim 7,

the determining the position of the satellite positioning point according to the distance between the foot and the nearest satellite reference point specifically comprises:

if the distance between the foot and the nearest satellite reference point is greater than a second threshold value, the satellite positioning point is not near the nearest satellite reference point;

and if the distance between the foot drop and the nearest satellite reference point is not greater than a second threshold value, the satellite positioning point is close to the nearest satellite reference point.

9. The method for improving the accuracy and effectiveness of train positioning at a curved track according to claim 8,

the second threshold is set according to the radian of the current curved track and the vertical length threshold set in the vertical matching algorithm, and specifically comprises the following steps:

Lt＝Ls*cos(α)

wherein, Lt is a second threshold, Ls is a vertical length threshold set in the vertical matching algorithm, and α is the radian of the current curved track.

10. The method for improving the accuracy and effectiveness of train positioning at a curved track according to claim 9,

the vertical length threshold set in the vertical matching algorithm is the maximum value of the satellite positioning longitude and latitude standard deviation under the global satellite positioning system.

11. A system for improving the accuracy and effectiveness of train positioning at a curved track, the system comprising:

the acquisition unit is used for acquiring the arc length and the line length between two adjacent satellite reference points at the bent orbit in the electronic map;

the first judgment unit is used for judging whether a new satellite reference point is added or not according to the difference value between the arc length and the line length;

the first processing unit is used for performing a vertical line matching algorithm according to a satellite positioning point and the satellite reference point;

and the mapping unit is used for determining the position of the satellite positioning point mapping according to the result of the vertical line matching algorithm.

12. The system for improving the accuracy and effectiveness of train positioning at a curved track of claim 11, further comprising:

the newly-added unit is used for adding a new satellite reference point;

the second judgment unit is used for judging whether the vertical line matching algorithm is successful or not;

the second processing unit is used for performing a vertical line matching algorithm according to the extension line of the connecting line of the two adjacent satellite reference points and the satellite positioning point;

and the third judging unit is used for judging the position of the satellite positioning point.

Technical Field

The invention belongs to the technical field of rail transit, and particularly relates to a method and a system for improving positioning accuracy and effectiveness of a train at a bent rail.

Background

Train positioning based on a satellite navigation system is one of important implementation technologies of next-generation train control systems. The train needs to calculate the running speed, distance and running direction of the train in real time, and report the position of the train to ground equipment based on LRBG (Last Relevant BaliseGroup, the latest Relevant responder group).

In the process of train satellite positioning, most positions (longitude and latitude) of a satellite positioning point are not on a train track, and the satellite positioning point needs to be mapped onto the train track, namely: and matching the satellite positioning point to a certain position on the electronic map of the train.

Disclosure of Invention

Aiming at the problems, the invention provides a method for improving the positioning accuracy and effectiveness of a train at a bent rail, which comprises the following steps:

acquiring the arc length and the line length between two adjacent satellite reference points at the curved orbit in the electronic map;

determining whether a new satellite reference point is added or not according to the difference value between the arc length and the line length;

performing a vertical line matching algorithm according to the satellite positioning point and the satellite reference point;

and determining the position mapped by the satellite positioning point based on the result of the vertical line matching algorithm.

Further, the determining whether to add a new satellite reference point according to the difference between the arc length and the line length specifically includes:

judging whether the difference value between the arc length and the line length is greater than a first threshold value, and executing a processing step according to a judgment result, wherein the processing step comprises the following steps:

if the difference value between the arc length and the line segment length is larger than a first threshold value, adding a new satellite reference point between the two adjacent satellite reference points, and returning to the step of obtaining the arc length and the line segment length between the two adjacent satellite reference points at the bent orbit in the electronic map;

and if the difference value between the length of the arc line and the length of the line segment is not larger than a first threshold value, executing the next step.

Further, the algorithm for matching the vertical line according to the satellite positioning point and the satellite reference point comprises the following steps:

making a vertical line of a connecting line of the two adjacent satellite reference points through the satellite positioning point;

judging whether the drop foot is on the connecting line of the two adjacent satellite reference points, wherein the judgment result comprises the following steps:

if the plumb feet are on the connection line of the two adjacent satellite reference points, the vertical line matching is successful;

and if the plumb is not on the connection line of the two adjacent satellite reference points, the plumb line matching fails.

Further, the determining the position of the satellite positioning point map based on the result of the vertical line matching algorithm comprises:

if the vertical line is successfully matched, mapping the satellite positioning point to a vertical foot;

and if the vertical line matching fails, judging the position of the satellite positioning point.

Further, the positions of the satellite positioning points include:

the satellite positioning point is near the nearest satellite reference point;

the satellite fix point is not near the nearest satellite reference point.

Further, if the satellite positioning point is near the nearest satellite reference point, mapping the satellite positioning point to the nearest satellite reference point, and positioning successfully;

and if the satellite positioning point is not near the nearest satellite reference point, the positioning fails.

Further, the position of the satellite positioning point is judged by the following steps:

making an extension line of a connecting line of the two adjacent satellite reference points;

making a perpendicular line of the extension line through the satellite positioning point;

and determining the position of the satellite positioning point according to the distance between the foot and the nearest satellite reference point.

Further, the determining the position of the satellite positioning point according to the distance between the foot and the nearest satellite reference point specifically includes:

if the distance between the foot and the nearest satellite reference point is greater than a second threshold value, the satellite positioning point is not near the nearest satellite reference point;

and if the distance between the foot drop and the nearest satellite reference point is not greater than a second threshold value, the satellite positioning point is close to the nearest satellite reference point.

Further, the second threshold is set according to the radian of the current curved track and a vertical length threshold set in a vertical matching algorithm, and specifically includes:

Lt＝Ls*cos(α)

wherein, Lt is a second threshold, Ls is a vertical length threshold set in the vertical matching algorithm, and α is the radian of the current curved track.

Furthermore, the vertical length threshold set in the vertical matching algorithm is the maximum value of the satellite positioning longitude and latitude standard deviation under the global satellite positioning system.

A system for improving the accuracy and effectiveness of train positioning at a curved track, the system comprising:

the acquisition unit is used for acquiring the arc length and the line length between two adjacent satellite reference points at the bent orbit in the electronic map;

the first judgment unit is used for judging whether a new satellite reference point is added or not according to the difference value between the arc length and the line length;

the first processing unit is used for performing a vertical line matching algorithm according to a satellite positioning point and the satellite reference point;

and the mapping unit is used for determining the position of the satellite positioning point mapping according to the result of the vertical line matching algorithm.

Further, the system further comprises:

the newly-added unit is used for adding a new satellite reference point;

the second judgment unit is used for judging whether the vertical line matching algorithm is successful or not;

the second processing unit is used for performing a vertical line matching algorithm according to the extension line of the connecting line of the two adjacent satellite reference points and the satellite positioning point;

and the third judging unit is used for judging the position of the satellite positioning point.

The invention expands the existing electronic map and the vertical line matching algorithm, increases a certain number of satellite reference points for the electronic map, and optimizes the vertical line matching algorithm so as to improve the accuracy and the effectiveness of the train satellite positioning. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

Fig. 1 shows a schematic diagram of a vertical line matching algorithm at a straight track according to the prior art;

FIG. 2 is a diagram illustrating a vertical line matching algorithm at a curved track according to the prior art;

FIG. 3 is a schematic diagram illustrating invalidation of a vertical matching algorithm at a curved track according to the prior art;

FIG. 4 shows an effective diagram of a vertical matching algorithm at a curved track according to the prior art;

FIG. 5 is a schematic flow chart illustrating a method for improving the accuracy and effectiveness of train positioning at a curved track according to an embodiment of the present invention;

FIG. 6 is a schematic diagram illustrating the addition of satellite reference points at a bend according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a vertical matching improvement algorithm according to an embodiment of the present invention;

fig. 8 shows a schematic diagram of a system for improving the positioning accuracy and effectiveness of a train at a curved track according to an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the case of train satellite positioning, the prior art scheme mainly uses a vertical matching algorithm based on an electronic map, and the use of the vertical matching algorithm is divided into two cases, including the use of the vertical matching algorithm under a straight track condition and the use of the vertical matching algorithm under a curved track condition. Specifically, the method comprises the following steps:

when in a straight orbit condition, fig. 1 shows a schematic diagram of a vertical line matching algorithm at a straight orbit according to the prior art, as shown in fig. 1, N1 and N2 are satellite reference points configured in an electronic map, wherein the satellite reference points are located on an orbit, M is a satellite positioning point, P is a foot, the foot point P is an operation position of a train in the electronic map, a connecting line of N1 and N2 is overlapped with the straight orbit, therefore, a vertical line connecting the N1 point and the N2 point is made through the point M, the foot P is on the straight orbit, that is, the satellite positioning point M is just mapped on the straight orbit, and a satellite positioning error cannot be introduced by the vertical line matching algorithm.

When in a bending condition, fig. 2 shows a schematic diagram of a vertical line matching algorithm at the bending position according to the prior art, as shown in fig. 2, N1 and N2 are satellite reference points configured in an electronic map, wherein the satellite reference points are located on an orbit, M is a satellite positioning point, P is a foot, and a connecting line of N1 and N2 does not coincide with the bending. And (3) making a vertical line connecting the point N1 and the point N2 when the point M passes through, wherein the foot P is on the connecting line of the point N1 and the point N2, but the foot P is not on the curved rail. The position calculated by adopting a vertical line matching algorithm is inconsistent with the theoretical position, a satellite positioning error is introduced, and the larger the radian of the orbit is, the larger the error is; the farther the adjacent satellite reference points are, the greater the accumulated error.

In addition, in the curved track, the vertical matching algorithm is adopted, and there is also a case that the positioning of the effective satellite positioning point fails, as shown in fig. 3. In fig. 3, N1, N2, and N3 are adjacent satellite reference points configured in the electronic map, and M is a train satellite positioning point. When the M point is exactly between the perpendicular N2N4 of the line segment N1N 2 and the perpendicular N2N5 of the line segment N2N 3, the satellite positioning failure is caused by adopting the perpendicular matching algorithm, and the greater the orbital arc, the lower the effectiveness.

Aiming at the requirements of the satellite positioning accuracy and the effectiveness of the train, the invention provides a method for improving the positioning accuracy and the effectiveness of the train at the bent rail, the method improves the existing vertical line matching algorithm, and as shown in fig. 5, the method comprises the following steps:

the method comprises the following steps: acquiring the arc length and the line length between two adjacent satellite reference points at the curved orbit in the electronic map;

for example, taking fig. 2 as an example, N1 and N2 are satellite reference points configured in an electronic map, and the lengths of an arc N1N 2 and a line segment N1N 2 are obtained, and the length of an arc N1N 2 is the length of a curved track.

Step two: determining whether a new satellite reference point is added or not according to the difference value between the arc length and the line length; in particular, the method comprises the following steps of,

judging whether the difference value between the arc length and the line length is greater than a first threshold value, and executing a processing step according to a judgment result, wherein the processing step comprises the following steps:

if the difference value between the arc length and the line segment length is larger than a first threshold value, adding a new satellite reference point between the two adjacent satellite reference points, and returning to the first step;

and if the difference value between the length of the arc line and the length of the line segment is not larger than a first threshold value, executing a third step.

Illustratively, taking fig. 2 as an example, the first threshold is illustrated by St, where the threshold St is set according to the actual train satellite positioning accuracy requirement. Judging whether the difference between the lengths of the arc N1N 2 and the segment N1N 2 is greater than the threshold St or not, and judging as follows:

if the difference between the lengths of the arc N1N 2 and the segment N1N 2 is greater than the threshold St, a new satellite reference point is added between the satellite reference point N1 and the satellite reference point N2. In this embodiment, a new satellite reference point N3 is added between the satellite reference point N1 and the satellite reference point N2, as shown in fig. 6. Returning to the first step, the lengths of an arc N1N 3 and a line segment N1N 3 and the lengths of an arc N3N 2 and a line segment N3N 2 are acquired, and then the second step is executed to respectively judge whether the difference between the lengths of an arc N1N 3 and a line segment N1N 3 and the difference between the lengths of an arc N3N 2 and a line segment N3N 2 are larger than the threshold St. If the length difference is larger than the threshold St, a new satellite reference point is continuously added between the two adjacent satellite reference points, the step I is returned, and the operation is repeated. Through continuous dividing the curved rail, the curved rail is divided into a plurality of parts by the whole according to the radian of the rail, and the radian of each part of the curved rail is controlled in a certain range, so that the radian of a single part of the curved rail is reduced to reduce the positioning error, thereby reducing the integral positioning error of the curved rail and improving the positioning accuracy of the train.

If the difference between the lengths of the arc N1N 2 and the segment N1N 2 is not greater than the threshold St, step three is performed.

In this embodiment, it should be noted that the position of the new satellite reference point N3 is preferably the position where the difference between the lengths of the arc N1N 3 and the line N1N 3 is equal to the threshold St, and the satellite reference points to be added subsequently also follow the position selection method, i.e. the principle of minimum satellite reference points.

Step three: performing a vertical line matching algorithm according to the satellite positioning point and the satellite reference point; in particular, the method comprises the following steps of,

1. making a vertical line of a connecting line of the two adjacent satellite reference points through the satellite positioning point;

2. judging whether the drop foot is on the connecting line of the two adjacent satellite reference points, wherein the judgment result comprises the following steps:

if the plumb feet are on the connection line of the two adjacent satellite reference points, the vertical line matching is successful;

and if the plumb is not on the connection line of the two adjacent satellite reference points, the plumb line matching fails.

Illustratively, taking fig. 3 as an example, the segment N2N4 is a perpendicular to the line connecting the satellite reference point N1 and the satellite reference point N2, and the segment N2N5 is a perpendicular to the line connecting the satellite reference point N2 and the satellite reference point N3. As can be seen from fig. 3, the satellite positioning point M is not located on the line segment N2N4 or on the line segment N2N5, and is located between the line segment N2N4 and the line segment N2N5, that is, a perpendicular line connecting the satellite reference point N1 and the satellite reference point N2 cannot be made through the satellite positioning point M, and a perpendicular line connecting the satellite reference point N2 and the satellite reference point N3 cannot be made through the satellite positioning point M, that is, a drop foot is not located on the connection line between the two adjacent satellite reference points, so that matching fails.

Illustratively, as shown in FIG. 4, line segment N2N4 is perpendicular to the line connecting satellite reference point N1 and satellite reference point N2, and line segment N2N5 is perpendicular to the line connecting satellite reference point N2 and satellite reference point N3. As can be seen from fig. 4, the satellite positioning point M is located on one side of the line segment N2N4 and is not located between the line segment N2N4 and the line segment N2N5, a perpendicular line connecting the satellite reference point N1 and the satellite reference point N2 is made through the satellite positioning point M, the foot is P, and the foot point P is located on the line connecting the two adjacent satellite reference points, so that the perpendicular line matching is successful.

Step four: and determining the position mapped by the satellite positioning point based on the result of the vertical line matching algorithm. Specifically, the determining the position of the satellite positioning point mapping based on the result of the vertical line matching algorithm includes:

if the vertical lines are successfully matched, mapping the satellite positioning points to the vertical feet, namely the vertical feet are the running positions of the train in the electronic map;

and if the vertical line matching fails, judging the position of the satellite positioning point.

Wherein the position of the satellite positioning point comprises:

the satellite positioning point is near the nearest satellite reference point;

the satellite fix point is not near the nearest satellite reference point.

If the satellite positioning point is close to the nearest satellite reference point, mapping the satellite positioning point to the nearest satellite reference point, and successfully positioning;

and if the satellite positioning point is not near the nearest satellite reference point, the positioning fails.

Further, the position of the satellite positioning point is judged by the following steps:

1. making an extension line of a connecting line of the two adjacent satellite reference points;

2. making a perpendicular line of the extension line through the satellite positioning point;

3. determining the position of the satellite positioning point according to the distance between the foot and the nearest satellite reference point, specifically:

if the distance between the foot and the nearest satellite reference point is greater than a second threshold value, the satellite positioning point is not near the nearest satellite reference point;

and if the distance between the foot drop and the nearest satellite reference point is not greater than a second threshold value, the satellite positioning point is close to the nearest satellite reference point.

Wherein, the second threshold is set according to the radian of the current curved track and the vertical length threshold set in the vertical matching algorithm, and specifically comprises:

Lt＝Ls*cos(α)

wherein Lt is a second threshold, Ls is a vertical length threshold set in a vertical matching algorithm, α is a radian of a current curved track, and Ls is a vertical length threshold set in the vertical matching algorithm and is a maximum value of a satellite positioning latitude and longitude standard deviation under a global satellite positioning system (GNSS).

Illustratively, taking fig. 3 as an example, a modification is made on the basis of fig. 3, and is shown in fig. 7 after the modification; the second threshold is exemplified by Lt. As can be seen from fig. 7, the satellite positioning point M is located between the vertical line N2N4 and the vertical line N2N5, and therefore the satellite positioning point M does not fall on the connection between the satellite reference point N1 and the satellite reference point N2, or on the connection between the satellite reference point N2 and the satellite reference point N3, and therefore it is necessary to continuously determine whether the satellite positioning point M is in the vicinity of the nearest satellite reference point, that is, whether the satellite positioning point M is in the vicinity of the satellite reference point N2, and the determination method includes:

the method comprises the following steps:

1. making an extension N2N 6 of a line segment N1N 2;

2. performing vertical line calculation according to the extension line N2N 6 and the satellite positioning point M, wherein the vertical foot is P;

3. calculating the distance L between the foot point P and the satellite reference point N2;

4. judging whether the distance L is larger than a threshold value Lt, wherein the judgment result is as follows:

a. if the distance L is greater than the threshold value Lt, the positioning is considered to be failed;

b. and if the distance L is not greater than the threshold value Lt, mapping the satellite positioning point M to a satellite reference point N2, namely the satellite reference point N2 is the running position of the train in the electronic map, and positioning successfully.

The second method comprises the following steps:

1. making an extension N2N 7 of a line segment N3N 2;

2. performing vertical line calculation according to the extension line N2N 7 and the satellite positioning point M, wherein the vertical foot is P;

3. calculating the distance L between the foot point P and the satellite reference point N2;

4. judging whether the distance L is larger than a threshold value Lt, wherein the judgment result is as follows:

a. if the distance L is greater than the threshold value Lt, the positioning is considered to be failed;

b. and if the distance L is not greater than the threshold value Lt, mapping the satellite positioning point M to a satellite reference point N2, namely the satellite reference point N2 is the running position of the train in the electronic map, and positioning successfully.

In the present embodiment, any of the above-described determination methods may be selected, and a determination method in which the distance L is small is preferable.

When the vertical line matching algorithm fails, the matching principle of the embodiment is added, so that the failure of train satellite positioning can be effectively reduced, and the effectiveness of train satellite positioning is improved.

In the embodiment, a method for expanding the existing electronic map and the vertical line matching algorithm is adopted, a certain number of satellite reference points are added for the electronic map, and the vertical line matching algorithm is optimized, so that the requirements on the accuracy and the effectiveness of the train satellite positioning are met.

Compared with the scheme that a vertical line matching algorithm is adopted at a straight orbit and a nearest matching algorithm is adopted at a bent orbit, in the embodiment, according to the requirement on the accuracy of train satellite positioning, only when the actual length of the bent orbit is greatly different from the straight connection length of the adjacent satellite reference points, a small number of satellite reference points are added on the electronic map, the vertical line matching algorithm is optimized, the complexity of the operation method is low, different thresholds are set according to different radians of the bent orbit, and the effectiveness of train satellite positioning is improved.

The invention also provides a system for improving the positioning accuracy and effectiveness of the train at the bent rail, and as shown in fig. 8, the system comprises an acquisition unit, a first judgment unit, a second judgment unit, a third judgment unit, a first processing unit, a second processing unit, a newly-added unit and a mapping unit. Specifically, the obtaining unit obtains the arc length and the line segment length between two adjacent satellite reference points at the curved track in the electronic map, and then transmits the obtained length information to the first judging unit.

The first judging unit judges whether a new satellite reference point is added or not according to the difference value between the arc length and the line length, and if the new satellite reference point needs to be added, the first judging unit sends the adding information to the newly added unit; if no new satellite reference point needs to be added, the first judgment unit sends an instruction to the first processing unit to execute the next step.

After receiving the adding information sent by the first judging unit, the newly adding unit adds a new satellite reference point, and then the acquiring unit acquires the arc length and the line length between two adjacent satellite reference points at the bent orbit again.

And the first processing unit performs a vertical line matching algorithm according to the satellite positioning point and the satellite reference point.

The second judgment unit judges the result of the vertical line matching algorithm of the first processing unit, and if the vertical line matching is successful, an instruction is sent to the mapping unit; if the vertical line matching fails, sending an instruction to a second processing unit;

the second processing unit carries out a vertical line matching algorithm according to the extension line of the connecting line of the two adjacent satellite reference points and the satellite positioning point;

the third judging unit judges the position of the satellite positioning point according to the result of the vertical line matching algorithm of the second processing unit and sends the position information of the satellite positioning point to the mapping unit;

and the mapping unit determines the position mapped by the satellite positioning point according to the result of the vertical line matching algorithm of the first processing unit and the position information of the satellite positioning point.

It should be noted that "first", "second", and "third" in this embodiment are merely for distinguishing purposes, and do not indicate a sequential relationship.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.